Sprag.



A. BENDLE.

SPRAG. APPLICATION FILED MAY s. 190B.

Patented Feb. 9, 1909.

ARTHUR BENDLE, OF .IOHNSTOWN, PENNSYLVANIA.

SPRAG.

ivo. 912,062.

Specification of Letters Patent.

Patented Feb. 9, 1909.

Application led May 8, 1908. Serial No. 431,681.

To all 'whom it may concern:

Be it known that I, ARTHUR BENDLE, a citizen of the United States,residing at Johnstown, in the county of Cambria and State ofPennsylvania, have invented new and useful Improvements in Sprags, ofwhich the following is a specification.

This invention relates to sprags for use in coal mines, and the objectof the invention is to provide a simple, cheap and efhcient device ofthis character adapted to be placed under the mine strata and adjustedto fit the various angles or slopes to protect the lives of miners bypreventing the falling of bodies of coal or slate when undermined.

TFilith these and other objects in view the invention resides in thenovel construction of elements and their arrangement in operativecombination hereinafter fully described and claimed.

In the accompanying drawings, Figure 1 is a longitudinal sectional viewof a sprag constructed in accordance with the present invention andtaken upon the line on a plane with the dotted lines 1*1 of Fig. 2. Fig.2 is a top plan view of the device. Fig. 3 is a horizontal sectionalview upon the line 3--3 of Fig. 1.

In the accompanying drawings the numeral 1 designates the body portionof the improved sprag. This body portion 1 is provided with a centraltubular member 2, provided with interior screw threads 3, and aplurality of angularly extending legs 4. These legs et are each.provided with a threaded aperture, adapted for the reception of thescrew members 5. These screw members 5 are each provided with acone-shaped bearing portion 6, preferably formed integral with thescrews. The screws 5 are adapted to be adjusted at various heights toprovide for the uneven surfaces of the `floor of the mine with whichthey are adapted to engage. The screw members 5 may be also providedwith locking nuts 7 adapted to engage the under face of the legs 4 andretain the screws in adjusted position.

The centrally arranged tubular portion of the body has its screw threads3 adapted for the reception of the threaded member 8 of a central member9. This member 9 has its upper extremity reduced to provide a shoulder10 adapted for the reception of the preferably squared toothed head 11of the device. The central member 9 has its body portion immediatelyabove the threads 8 provided with a transverse slot adapted for thereception of an operating rod 12.

From the above description, it will be apparent that the device may beadjusted to agree with the various angles of the surfaces which it isadapted to engage, and that the device is extremely sim' le inconstruction, as well as thoroughly effbctive in operation. Theextension provided upon the central member 9 whereby the head 11 ispositioned upon this member is annular in cross section, so as to allowthe handle 12 to rotate the screw S without interfering with the head 11by causing it to turn in its engagement.

I-Iaving thus fully described the invention what is claimed as new is:

A device for the purpose set forth comprising an interiorly threadedbody portion, right angularly disposed leg sections integrally formedwith the body and extending loutwardly therefrom, said leg sectionsterminating in a plane with the base of the body and being each providedwith athreaded orifice, threaded members having their extremitiesprovided with cone shaped sprags for these openings, locking elementsupon these threaded members, a threaded element having a reducedextension for the interiorly threaded body, a removable head upon theextension of the threaded element, teeth upon this head and a handle forrevolving the threaded element.

In testimony whereof I affix my signature in presence of two witnesses.

ARTHUR BENDLE. Vitnesses ALEX N. HART, JOHN H. STErHnNs.

